Size composition for artificial silk



Patented Aug. 6, 1935 UNITED STATES PATENT OFFICE.

2,010,134 SIZE CODIPOSITION FOR ARTIFICIAL SILK Herman S. Bosland,Paterson, N. J and Frederick G. La Piana, Forest New York No Drawing.

5 Claims.

In the past, the weaving of and threads or rayon, and particularlycellulose acetate ficulties. The percentage of fabrics of artificial sifilaments type, has

from yarns artificial silks and lks of the been attended with difbreaksin the threads is excessive, and there is a tendency for the threads tobecome snarled.

aware, none of So far the sizes heretofore met these difficulties. I

relates more particularly to warp This invention sizing of suchmaterials, as

In dealing w finish sizing.

artificial silk yarn tinuous fibers, difi'er than in the treatmenfibers, such as cotton and wool, or

yarns of real silk. In the fabrics made of cotton and wool, the

due to the many such yarns, the

marily intended to act as a shield fraying by pasting and On the otherhand, i fabrics from artificial silk yarns continuous threads and thusthere is need for pasting loose ends down as in cotton yarns, forexample.

threads are generally so ton, wool and re ency to snap. artificialsilks,

holdin in the the However, these al silk, and have a as a strengtheningand lubricating prevent the snapping of the same time functioning as ashield fraying or snarling s Furthermore, in warp ticed, the size is aswe are used with this class of textile materials has satisfactorilydistinguished from ith yarns such as s, which are composed of conentproblems are met with t of yarns made up of short in treatingmanufacture of textile yarns tend to fray as they pass through the reedsand other parts of the loom,

and in warp sizing loose ends, size is prito prevent loose ends.

n manufacturing textile yarns have not the continuous mewhat weaker thancotgreater tend- Therefore, in the warp sizing of the size shouldoperate primarily element to threads while at the to prevent hould athread snap.

sizing as ordinarily practo be removed from the threads after the fabrichas been formed. A

silk is character-- that it is generally weaker when immersed in wateror is in a wet condition and this is not true of yarns such as cotton,wool and real silk. Accordingly, artificial silk fabrics cannotordinarily be subjected to such a severe processing for the removal of awarp size as is fabric made from cotton. wool possible with a and realsilk.

In weaving ce yarns a further that such yarns ulose acetate yarns andsimilar with, namely,

r-repellent,

Inc., a corporation of Application September 9, 1931,

erial No. 561 988 and consequently there is a tendency for the size tobe repelled from the yarns during the sizing treatment or to adherepoorly to the yarn.

It is an object of the present invention, therefore, to provide a sizehaving the above-mentioned strengthening and lubricating characteristicsand which is also readily removable from the fabric after the formationthereof.

It is a further object of the present invention to provide a size whichwill readily wet and stick 10 to artificial silk yarns and threads, andwhen applied to the same will strengthen, them and give them a smoothcoating, permitting them to slip freely through the reeds and otherparts of the loom with which they contac We have found that sizes whichhave ordinarily been used for sizing cotton and wool, such as thevarious starches, dextrins, natural gums, gelatines and animal glues,are unsatisfactory when it is attempted to use them for the sizing ofarti- 20 ficial silk yarns and filaments, and particularly for warpsizing, for the reason that such sizes, either cannot be successfullyapplied to artificial silks due to the water-repellent character ofcertain of such silks or do not have the desired 25 properties ofstrengthening the yarns and being easily removed therefrom. We havefound further that casein, and particularly certain caseinbase sizes,.can be successfully applied to artificial silk threads and yarns, andhave all of the so desired characteristics above mentioned.

We are aware of the fact that casein in combination with various othersubstances has heretofore been proposed by others to be used as a finishsize for cotton,-wool and real silk fabrics and as a coating for fabricsand paper where it is desired to make the fabric or paper waterproof, e.g., in finishing book cloth; but so far as we are aware, casein has notbeen used heretofore either alone or in any combination as a warp sizeor on artificial silk fabrics. However, the problem that presents itselfin the weaving of artificial silk or rayon and particularly celluloseacetate yarns, is quite different. In the first place, a warp sizingtreatment of yarns and threads preparatory to weaving is given for thepurpose of imparting certain properties and thereby to overcome certaindifiiculties that are not presented in treating the finished fabric.Furthermore, certain artificial silk yarns and threads and particularlythose derived from cellulose acetate are more or less water-repellentandthis has caused difiiculties to arise in eflecting a sizing of suchyarns, due to the fact that there has been a tendency for the'sizeshereto- 56 Sugar 1 g Sodium fluoride fore used to be repelled from theyarn during the sizing operation. On the contrary, our composition isnot repelled from the yarn but wets and sticks to it, strengthening andlubricating it, and at the same time, is readily removable therefrom.

Our invention, therefore, resides in the discovery that casein alone orin combination with certain other substances is especially adapted foruse in preparing a size for sizing artificial silk yarns and threads,and particularly for warp sizing thereof. While casein alone constitutesa satisfactory size under favorable circumstances, there are particularadvantages in adding other substances, such as corn sugar or a similarhygroscopic material, dextrin or dextrinized starchcontaining materialand/or glue to the casein in forming a size for this purpose. It is alsodesirable, but not essential, to add a preservative such, for example,as sodium fluoride.

In the preparation of a casein size we have found that it isadvantageous in certain cases to add to the casein a substantial amountof sugar or a similar hygroscopic material with or without a smallamount of a preservative, such as sodium fluoride. A suitable size ofthis type may be prepared from a composition consisting of from about 65to 90 parts by weight of casein, and 10 to parts by weight of a suitablehygroscopic material, such as cane sugar, corn sugar or glycerine, withor without a small percentage of a suitable preservative. A specificcomposition which has been highly satisfactory in service consists of amixture containing casein, sugar and sodium fluoride in about thefollowing proportions by weight:

Casein '70 parts 27 parts 2- parts We have discovered further that it issometimes advantageous to add to a mixture such as above mentioned, asuitable amount of dextrin or a dextrinized starch-containing material;and in certain instances, for example, when it is desired to keep theprepared size from congealing on prolonged standing, it is advantageousto substitute glue, which may be either of animal or vegetable origin,for all or a part of the dextrinous material. A suitable size of thistype may be prepared from a composition consisting of from about 50 ,to80 parts by weight of casein, to 10 parts of dextrin or a more or lessdextrinized starch-containing material, and the balance corn or canesugar or other suitable organic hygroscopic material. A specific exampleof such a composition is as follows:

Casein 70 parts by weight Dextrinized tapioca flour 20 parts by weightCorn sugar 10 parts by weight The compositions of the present inventionmay to the places where they are to be used. It will be understood thatthe casein must be brought into a soluble form by treatment with asuitable alkaline agent, for example ammonia. This treatment may precedethe mixing step or be carried out after the mixing step and conductedeither in the dry way, as by contacting the casein or the dry mixturewith gaseous ammonia, or by incorporating the alkaline agent into thebath used in preparing the size from the dry mixture and thoroughlydisseminating such agent through the liquid mixture.

In order to prepare and apply a size from the compositions aforesaid, itis recommended, by way of example, that to about 10 pounds ofcomposition there be added about 8 gallons of water and 7 pounds of aneutral soluble oil or other softener, for example castor oil or oliveoil which has. been sulphonated to a desired degree and thenneutralized; a small amount of ammonia, say, 1 pint of 26 B. ammonia,may be added if desired. The resultant mass is then mixed and heated toabout 180 F. This procedure contemplates the pretreatment of the caseinor the dry mixture in the dry way with a casein solubilizing agent. Incase the casein is in the insoluble form when brought into the aqueousliquid bath, its solubilization may be efiected by adding a suitablequantity of aqueous ammonia and thoroughly stirring. The sizing preparedas above described is now ready for use and may be conveniently appliedto the material to be treated at a temperature of about 140-160 F.

This constitutes in part a continuation of our application Serial No.419,200, filed January 7, 1930, now Patent No. 1,914,989.

We claim:

1. A composition for use in preparing a warp size for artificial silksconsisting of a preponderant proportion of casein and an organichygroscopic material.

2. A composition for use in preparing a warp size for artificial silksconsisting of a preponderant proportion of casein, a hygroscopicmaterial, and a preservative.

3. A composition for use in preparing a warp size for artificial silksconsisting of a preponder-' ant proportion of from 65 to 90 parts byweight of casein and from 10 to 35 parts by weight of an organichygroscopic material.

4. A composition for use in preparing a warp size for artificial silksconsisting 01 about 70 parts by weight of casein, about 27 parts byweight of an organic hygroscopic material, and about 2 parts by weightof sodium fiouride.

5. A process of preparing a warp size composition for artificial silkyarns which consists in dissolving a mixture consisting of apreponderant amount of casein and a hygroscopic material in an alkalineaqueous solution.

HER s. BOSLAND. FREDERICK G. LA PIANA.

